1. Field of the Invention
Apparatuses consistent with the present invention relate to a mobile radio frequency identification (mRFID) reading, and more particularly, to mRFID reading with reduced power consumption and cost by a compact-sized mRFID reading device.
2. Description of the Related Art
A Radio Frequency Identification (RFID) system generally includes a reader, an antenna, an electronic tag, a server, and a network. The reader reads recorded data from the electronic tag or records the data in the electronic tag. The antenna exchanges the recorded data of the electronic tag with the predefined frequency and protocol.
A mobile RFID (mRFID) technology has been achieved by combining a RFID system and mobile communications. In a mRFID system, an electronic tag, a reader, an antenna and a processing module are attached to a mobile communication terminal, so that the mobile communication terminal can read information from external electronic tags and provide helpful information to users, or transfer information to other mobile communication devices through its electronic tag.
FIG. 1 is a schematic circuit diagram of a related art mRFID reader. The mRFID reader in FIG. 1 includes a transmitting circuit 1b and a receiving circuit 1a. 
The transmitting circuit 1b generates a transmission signal of certain frequency that is transmitted to a tag. The transmitting circuit 1b modulates a transmission signal using a Single Side Band (SSB) or Double Side Band (DSB). At 1b, the SSB sends both of I-signal and Q-signal, while the DSB sends only one of the I-I-signal and the Q-signal. But, At 1a, receiving circuit needs both I signal and Q signal because receiver doesn't know a distance between tag and transmitter(reader).
The receiving circuit 1a processes I-signal and Q-signal, and includes an I-signal processing circuit 2a, a Q-signal processing circuit 2b, a local oscillator 7a, an IQ combiner 8, and a baseband signal processing block 9.
The I-signal processing circuit 2a and the Q-signal processing circuit 2b are configured in the same structure, including a Low Noise Amplifier (LNA) 3a, 3b, a mixer 4a, 4b, a filter 5a, 5b, an amplifier 6a, 6b, and an Analog-to-Digital Converter (ADC) (not shown).
The local oscillator 7a provides the mixers 4a, 4b of the I-signal processing circuit 2a and the Q-signal processing circuit 2b with a carrier signal, respectively. The I-signal and the Q-signal are at 90° phase difference, and the carrier signals being provided to the mixers 4a, 4b of the I-signal processing circuit 2a and the Q-signal processing circuit 2b are at 90° phase difference from each other, accordingly. To keep 90° phase difference between the carrier signals, a phase difference generating unit 7b is provided to the Q-signal processing circuit 2b to generate 90° phase difference to a carrier signal being transmitted from the local oscillator 7a. 
The IQ combiner 8 receives the I-signal and the Q-signal which are processed at the I-signal processing circuit 2a and the Q-signal processing circuit 2b, and combines the received signals into a single signal.
The baseband signal processing block 9 receives the signal from the IQ combiner 8, and reads the received signal by performing processing such as decoding and thus acquires information of the tag.
As explained above, the related art mRFID reader includes the I-signal processing circuit 2a and the Q-signal processing unit 2b of the same structure, to process the I-signal and the Q-signal, respectively. Meanwhile, in order to compensate for the delay of receiving a reflected signal from the tag, that is, to compensate for a phase delay according to the distance between a tag and a mRFID reader, the related art mRFID reader processes the I-signal and the Q-signal separately, and then combines the processed signals.
The related art mRFID reader has a large size to accommodate the I-signal processing circuit 2a and the Q-signal processing circuit 2b. Additionally, the requirement to accommodate the associated components and the generally large components such as mixers 4a, 4b or filters 5a, 5b further increases the size of the mRFID reader. As the size of the mRFID reader increases, a mobile communication terminal has to be sized larger to accommodate the mRFID reader. This goes against the customer's demands for compact size products. Additionally, the related art mRFID reader has also the problems of high power consumption and unit price.